Beseler/Minolta 45a minus number question

[ic-racer]

When doing the ring-around you used the "settings that produced the best density level" to start the ring-around, yes?

So if -15 +5 looks best, you have to manually (in your head or with pencil and paper or calculator) subtract 15 and add 5 from you starting "settings that produced the best density level" The ring-around is bracketing exposure by the amount indicated in the table.

 

[Chan Tran]

I don't see the head is good for B&W. Additive color printing is good but I would rather do it in another way not in the strobing manner.

 

[Wisner]

IC-Racer, thank you for your reply. Yes, I started the ring-around at 120 120. I found that by doing a test strip starting at 0 0 and then adding one stop or 30 30, 60 60 etc. until I hit 120 120.

120 120 was a little light and about 1/2 grade too flat. I was going to just start upping the blue and adding a little density by upping both. However, I read the manual again and hit the data button while in 120 120 and did a full ring-around. The -15 +5 is what looked good for exposure #4. According to the manual I should enter those numbers in the color mode. Problem is minus numbers can't be input and that is where I quit and started this thread.

I now have a better understanding of the unit. I do have a question, if I wanted to dial in a grade 3 filter what would I do? I am pretty good at looking at my negatives and knowing what grade the negative will need. The manual has listed all of the grades, however, many of them use minus numbers. From your conversation I gather once I have the correct density and wanted a grade #3 I would just add or subtract the manuals numbers from my correct density numbers. For example, if I am at 120 120 for density and I want a grade #3 - the manual states to use -30 G and +10 B for a grade #3. If I apply that to my 120 120 then my numbers would be 90 130, correct?

The next question is about density for the above calculation. Exposures seem to work with density units or .30 is one stop, so if I use the -30 G and +10 B, for grade 3 from he manual, then the -30 would be one stop lighter and the +10 B would be .1 or 1/3 stop or 30% darker. Add this together I would need to increase both numbers by 2/3 stop or add .20 to both numbers. If I am thinking correctly, then the 90 130 would need to be 110 150. Is my calculation of 110 150 correct for keeping the density the same as the 90 130 numbers when adjusting for a grade #3?

Just attempting to fully understand this piece of equipment so I can concentrate on making quality fine art prints and not concentrating on the equipment.

Thank you for your time.

 

[ic-racer]

120 120 was a little light and about 1/2 grade too flat. I was going to just start upping the blue and adding a little density by upping both. However, I read the manual again and hit the data button while in 120 120 and did a full ring-around. The -15 +5 is what looked good for exposure #4

Then use 105 and 125. If too light subtract 5 from both. If too dark add 5 to both. You may be making this to complicated.

This is a good head for B&W printing. Much better control than the old two lamp cold light that had a box with two knobs.

 

[Wisner]

Would just like to say thank you to all for your knowledge and input. I have buried myself in my darkroom for the last few days with the hops of understanding the 45a. Well, I can state, the 45a is a perfect light source for black and white printing. I am know printing with blue and green filters at the same time and am able to completely control the density and contrast of my prints. Split contrast printing is next.

I was sent a couple of 45a manuals from members of this site, the manual I purchased online is very old and very short. The .jpg manuals are in a zip file in .jpg format. I have taken the .jpg images and imported them to Adobe Acrobat for the purpose of combining all .jpg images into one document. The PDF manual is now much easier to read and print. The new manual is 78 pages, my old manual is 39, quite a difference. I have created a PDF manual from the .jpg images for the purpose of creating a single PDF manual that would be easier to read and print. I would be happy to post the completed PDF manual on this site for any and all to download, that is, as long as the .jpg document's aren't protected by a copyright. I can't imagine an outdated and no longer supported manual would be under copyright protection.

Just send me an email if you would like a copy of the newly created PDF manual.

Again, thank you to all who gave valuable input that put me in the right direction.